1. Field of the Invention
The present invention relates to a fuel cell device comprising a fuel cartridge that contains methanol mixed solution fuel such as methanol water solution and a direct methanol fuel cell on which the fuel cartridge is set, and also to the fuel cartridge and a fuel cell.
2. Related Art
Thanks to the advancement in the latest electronic technology, telephones, notebook type personal computers, audio/visual devices, mobile terminals, and some others have been made compact and accordingly become very much popular as handy electronic devices. A fuel cell power supply is regarded as a power supply for these handy electronic devices. Since the fuel cell converts electro-chemically the chemical energy contained in the fuel directly into electric energy, it does not require any power drive needed for a generator, which is normally employed in an internal combustion engine, such as an ordinary engine generator. Accordingly, possibility of realization of a small generation device by using the fuel cell is very high. In addition, since the fuel cell continues generation as long as the fuel is supplied, it is no longer necessary to stop operating a device including a load temporarily for charging as is needed in using general secondary batteries.
For a generally known type of the fuel cell, hydrogen generated by reforming the city gas is used as fuel. While the operating temperature of the fuel of this type is higher than 80° C., there are available fuel cells that operate at a room temperature, one of which is a type that oxidizes liquid fuel directly on the fuel electrode of a fuel cell. A direct methanol fuel cell (DMFC) is a typical one, which directly oxidizes methanol.
A method of supplying fuel to the fuel cell is, for example, to fill a fuel cartridge with the fuel for generation and set the fuel cartridge on the fuel cell so that the fuel for generation is supplied from the fuel cartridge to the fuel cell. (See the Patent Document 1, for example)
[Patent Document 1] Japanese Application Patent Laid-open Publication No. 2003-45468 (Summary)
As the fuel for the direct methanol fuel cell, a mixed solution of methanol and pure water has been studied. The concentration of methanol in the mixed solution has a proper range depending upon the characteristics of the fuel cell and, if the fuel having the concentration greatly out of the proper range is supplied, the fuel cell does not satisfactory output performance and, furthermore, it may possibly give adverse effect on the members constituting the fuel cell. Accordingly, it becomes necessary in connecting the fuel cell cartridge with the fuel cell to check whether the fuel contained in the fuel cartridge is proper one for the fuel cell.